Shoes and sandals typically include an upper joined to a sole assembly. The sole assembly commonly includes an outsole, a midsole and an insole. While in some cases these components can be cut out of sheet stocks of various types, it is becoming ever more popular particularly in the cases of sport shoes, sport sandals, running shoes and the like to mold the various sole components and join them together using glues, heat and/or pressure. We have recently introduced a line of sports shoes and sandals which can be characterized as having a substantial degree of covering over the wearer's toes. In the case of sandals, this provides an unprecedented degree of protection to the wearer's feet and especially toes. It also imparts a distinctive and attractive design element to the footwear and can contribute to durability.
This toe covering can be achieved by integrally molding the toe protection into the outsole such that when the outsole is incorporated into the footwear the desired toe protection is provided. This approach can be seen in U.S. Pat. Nos. D 498,575 and D 498,523, issued from U.S. Ser. Nos. 29/173,098 and 29/173,099, filed on Dec. 20, 2002. As set forth herein, we have now found that the toe protection can also be provided by the combination of a toe cap integrally molded into the midsole and an upward-sweeping toe protection area integrally molded into the outsole to correspond to and cover at least a portion of the integrally-molded toe cap on the midsole.
This sort of midsole construction presents a difficulty in manufacturing. The materials employed in midsoles are most commonly foamed materials that are somewhat flexible and resilient. However, the midsole does serve an important role in defining the overall shape and flexibility of the final footwear product. In this role the midsole needs to have a substantial degree of structure and rigidity. This needs to be accomplished with a molded midsole as molding is the most cost effective and accepted way to form a midsole. This means that the shape in which the molded midsole is incorporated into the footwear product should correspond closely to the shape into which it has been molded so that this shape can be maintained during manufacture and into the final footwear product.
When molding a midsole having a substantial toe covering or cap a special problem occurs. A conventional molding process can not be easily used. For a conventional midsole having a bottom surface and a top surface and optional sidewalls that are either vertical or gradually outwardly flaring but not having a toe cap a simple two piece injection mold can be used with the female section of the mold defining the bottom surface and the outside surface of any side walls and the male part of the mold defining the top or inner surface of the midsole and the inside surface of any side walls. This mold can be conventionally closed to make the midsole and when opened after injecting the midsole foam, permitting the molded part to be simply lifted out. The presence of the integrally-molded toe cap changes this considerably as the overlaying toe piece makes it difficult if not impossible to form the midsole with a conventional two piece mold as the female mold section would essentially surround the outer portion in the toe region with the male section present within the toe section and this would prevent the direct separation of the two mold halves and simple removal of the product midsole.
The prior art includes the following United States Patents and Applications which describe multi-piece midsoles: U.S. Pat. Nos. 130,162; 168,051; 3,444,572; 4,676,010; 6,405,456; 6,516,540; and 6,715,218 and Applications No. 2002/0184793 and 2003/0172458.